Optimizing bottom-cut shape for melting performance in horizontal latent heat storage tank

Purpose Latent heat thermal energy storage (LHTES) systems represent a pivotal component in solar energy utilization, exhibiting vast potential for diverse applications. Despite the notable enhancement in heat transfer efficiency achieved by incorporating metal foam, the thermal resistance issue at the bottom poses a challenge to the overall system efficiency, and the system is optimized by designing the bottom shape. The purpose of this study aims to improve these topics. Design/methodology/approach This study is devoted to exploring the bottom optimization design scheme, constructing a numerical model and analyzing key parameters such as melting fraction, full melting time, melting front progression, temperature distribution, streamline, Grashof number and heat storage capacity to improve the heat storage performance of LHTES. Findings The findings of this study reveal that the bottom-concave arc LHTES unit demonstrates the most effective optimization, surpassing the bottom-crosscut and bottom-convex arc configurations in comparison to the annular design, and the bottom-concave arc LHTES unit with a height of 19.44 mm exhibits a 23.19% reduction in full melting time. Additionally, this study evaluates the impact of bottom optimization on natural convection, as indicated by the Grashof number, highlighting the heat transfer performance of the concave bottom arc with a height of 19.44 mm is improved by up to 20.04% compared to the annular configuration. Originality/value In this study, the shape optimization is carried out to improve the efficiency of the system and provide theoretical basis and practical guidance for the bottom optimization design of LHTES system.